Typically, pistons have been used to extend a piston rod out of a cylinder for providing the force necessary to perform a variety of functions. Some of these functions include compressing materials to produce bricks, stamping, shearing, forming, etc. In performing such functions the output force provided at the end of the piston rod must be of a predetermined high magnitude thereby requiring the fluidic working pressure of the fluid actuator to be very high. However, the fluid actuator, in order to provide such high pressure outputs, necessarily must be very large to handle such high working pressures. Additionally, the external fluid lines must also be very large and bulky to convey the fluid under the required working pressure into the cylinder of the fluid actuator.
The present invention overcomes the above noted difficulties by providing a fluid actuator system with means for internally increasing the fluid pressure therein.
The fluid actuator system of the present invention includes a pair of fluid actuators defined by a pair of cylinders having bores which are disposed for communication with each other. Each cylinder is provided with fluid inlets and outlets and the bore of each cylinder has a piston and piston rod reciprocally mounted therein. An end closure assembly, common to both actuators, includes a member which is provided with an axial bore to receive the piston rod of the first fluid actuator therein responsive to displacement of the piston/piston rod by working fluid pressure. The fluid inlet of the second cylinder is also provided in the end closure member and directs working fluid into the axial bore of the closure member and the second cylinder prior to the piston and piston rod of the first fluid actuator being displaced. Responsive to movement of the piston rod of the first fluid actuator into the bore of the end closure member, fluid in the axial bore of the end closure member forced against the piston face of the piston of the second fluid actuator for displacement of the piston rod of the second fluid actuator.